MAP 1C is a microtubule-activated ATPase which translocates microtubules in vitro and has dynein-like properties.
MAP 1C is a microtubule-activated ATPase which translocates microtubules in vitro and has dynein-like properties.
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DOI：
10.1083/jcb.105.3.1273
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发表时间：
1987-09
期刊：
影响因子：
--
通讯作者：
Vallee RB
中科院分区：
文献类型：
--
作者：
Paschal BM;Shpetner HS;Vallee RB
我们观察到，来自大脑的一种高分子量微管相关蛋白（MAP）表现出与微管的核苷酸依赖性结合。我们将该蛋白质鉴定为 MAP IC，之前在该实验室中将其描述为标准微管制剂的次要成分（Bloom, G.S., T. Schoenfeld 和 R.B. Vallee, 1984, J. Cell Biol., 98:320-330）。我们发现 MAP 1C 在没有核苷酸的情况下制备的微管中富集。这些制剂中也含有驱动蛋白，但可以用 GTP 专门提取。随后用 ATP 提取微管，可以制备高度富集 MAP 1C 的级分。进一步纯化后，两种活性与 MAP 1C 共分离，即微管激活的 ATP 酶活性和微管易位活性。这些活性表明蛋白质在细胞质运动中的作用。 MAP 1C 与衣藻鞭毛动力蛋白β重链共电泳，沉降系数为20S。在存在钒酸盐和 ATP 的情况下暴露于紫外线会导致产生 MAP 1C 的两个大片段。这些特征表明 MAP 1C 可能是轴丝动力蛋白的细胞质类似物。
We observe that one of the high molecular mass microtubule-associated proteins (MAPs) from brain exhibits nucleotide-dependent binding to microtubules. We identify the protein as MAP IC, which was previously described in this laboratory as a minor component of standard microtubule preparations (Bloom, G.S., T. Schoenfeld, and R.B. Vallee, 1984, J. Cell Biol., 98:320-330). We find that MAP 1C is enriched in microtubules prepared in the absence of nucleotide. Kinesin is also found in these preparations, but can be specifically extracted with GTP. A fraction highly enriched in MAP 1C can be prepared by subsequent extraction of the microtubules with ATP. Two activities cofractionate with MAP 1C upon further purification, a microtubule-activated ATPase activity and a microtubule-translocating activity. These activities indicate a role for the protein in cytoplasmic motility. MAP 1C coelectrophoreses with the beta heavy chain of Chlamydomonas flagellar dynein, and has a sedimentation coefficient of 20S. Exposure to ultraviolet light in the presence of vanadate and ATP results in the production of two large fragments of MAP 1C. These characteristics suggest that MAP 1C may be a cytoplasmic analogue of axonemal dynein.